I'm a big fan of using PSConfig during SharePoint installation and configurations - mainly because the default Central Administration content database ends up with a GUID in the database name if left to its own naming conventions. I prefer to explicitly name the database to avoid the lovely GUID name.
So, along those lines, I usually use something like the following:
Psconfig –cmd configdb –create –server MyDatabase –database MOSS_Config –user MyDomain\MyAccessAccount –password MyPassword –admincontentdatabase MOSS_AdminContent
What I've found today is that this doesn't exactly work with Stand-alone implementations - which I commonly use for demo environments. You can still use psconfig, but you can't specify the username and password. If you try, you'll get something like: "When installed in standalone mode, you cannot specify a farm administrator user account or password. The local account NetworkService becomes the farm administrator by default when installed in standalone mode.". You also cannot specify a server. What you end up with as a command is something like the following:
Psconfig –cmd configdb –create –database WSS_Config –admincontentdatabase WSS_AdminContent
FYI - The psconfig /help shows the command as follows:
Psconfig –cmd configdb –create –server <SQL_servername> –database <name_of_precreated_configdb> –user <domain\dbaccessaccount> –password <dbaccesspw> –admincontentdatabase <name_of_precreated_admincontentdb>